Other versions of the legendarium

Elmo was developed to explain the reference in The Silmarillion that Celeborn was a "kinsman of Thingol". One of his solutions was to establish Celeborn as a nephew of Thingol.

In other, later writings, Celeborn is made into a Telerin Elf, and a relative of Olwë of Valinor instead, but this was not further developed or published.

It therefore remains unsure if Elmo would have a place in the Middle-earth canon, as his position in the royal Sindarin family tree disappeared. Slightly later writings however make Círdan a descendant of Elmo, making him a kinsman to Thingol (and Celeborn). Certain is that Círdan had silver hair, a trait which otherwise only ran in Elwë and Olwë's family line.